Influence of the ability to roll the tongue and tongue-training parameters on oral motor performance and learning

Training of tongue function is an important part of rehabilitation of patients with brain damage. A standardized tongue-training task has been shown to induce cortical plasticity. This study tested the possible influence of the natural ability to roll the tongue and modulations of tongue-training parameters on tongue-training performance.

A total of 44 healthy adult subjects participated. 29 subjects (15 with and 14 without ability to roll their tongue) performed 1h standard tongue-training task. Another 15 subjects participated in 2 sessions: Standard and Modulation in randomized order. Standard session: 1h tongue-training with fixed training parameters; Modulation session: 1h tongue-training with modulation of training parameters every 20 min (3 different settings - A, B, C, with different timing of task). Perceived task difficulty was evaluated on a 0-10 numerical rating scale (NRS).

All participants improved performance during training (P<0.001). The ability to roll the tongue did not influence tongue-training performance (P=0.617). Modulation of training parameters influenced baseline training performance (P<0.018) and improvement (P=0.039). The mean perceived difficulty on NRS was: Standard: 6 ± 2; Modulation: A: 6 ± 2; B: 7 ± 1;C: 4 ± 1. Perceived task difficulty (ρ=-0.740, P<0.001) and performance improvement (ρ=-0.610, P<0.001) were inversely correlated with baseline training performance.

The natural ability to roll the tongue did not influence tongue-training performance. Modulation of tongue-training parameters by alteration of timing of the training task influenced tongue-training performance and perceived task difficulty.